It is also morally wrong to attack with the intent to kill.
Would it be morally right, if you attack with the intent to injure just to give the intruder enough excuse to kill you? when you have a young wife and young girls in your house, forget about morality, save their pussies from getting jumped hard.
I mean that means there's at least four of you in the house, so you could be able to intimidate them enough.
Although, I would side with attacking with intent to kill if you feel that you're going to be killed and your family attacked/killed also.
a 70+ year old would probably be quite fragile at that age and so should've probably used all the force he could on a young(er) intrudor.